This invention relates to an electrical signal transmission system for communicating information, including control signals, between a central station and a selected location, or point, at any one of several remote stations. More particularly, the invention provides a signal communication system for monitoring any selected one of many remote points, and for effecting a control operation at a selected point.
A feature of the system is the capability of operating with each of a large number of remote points with minimal interconnecting communication paths or channels, and with relatively simple, i.e. noncomplex, equipment, both at the central station and at each remote, point-controlling, station.
The invention is useful, for example, in monitoring conditions as in a fire detection system in a large, multiple-unit building, and for providing control at a remote location responsive to a condition sensed there. Another typical application is in monitoring and controlling the operation of a pipeline, with the remote points at successive locations along it. An advantage of the invention is that it provides such systems with high flexibility in system organization and information communicating capability, with both low cost equipment and low cost installation, relative to prior practices.
Prior art communication systems for monitoring fire, pipeline operation, and like conditions, and for providing control operations at the remote locations being monitored, generally require complex equipment or numerous communication channels between the central station and the remote locations. Consequently the prior systems are characterized by relativey high cost for both equipment and for installation.
It is an object of this invention to provide improved equipment for communicating information -- including data, control, and voice signals -- between a central station and any selected remote point.
In particular, it is an object to provide an improved multiple-point communication system for monitoring fire detecting test points, and for effecting control at such points where desired, at lesser cost than is available with prior equipment of comparable capability.
Another object of the invention is to provide a system logic organization for addressing any one of multiple points for communication with a central station, which can be implemented at lesser cost than heretofore practiced.
It is also an object that such multiple-point communication equipment of the foregoing character operate with relatively small electrical power consumption.
A further object is that the communication system of the above character have high flexibility in terms of rearrangement of the system and in terms of the kind of information being communicated.
Another object of the invention is to provide a communication system of the above character which operates with relatively high reliablity.
Other objects of the invention will in part be obvious and will in part appear hereinafter.